MSD questions
 

I'm preparing to install an MSD box and coil on my carbed 2.2. I've been through miles of archives on this but still need some advice.

Details: MSD 6TN with external Soft Touch rev controller. SS coil.



#1. Plug wires- MSD says not to use with solid core wires. I've seen advice both ways on this. I have 7mm Bosch silicone wires. Will these work or do I have to replace them with spiral wound?

#2. Rotor- I've seen several threads about burned rotors with these systems. One suggestion was to go to a solid rotor. I picked up the suggested Echlin EP141 (VW) rotor, but it does not fit my Bosch dizzy. It seems to be made for a tapered shaft. Does anyone know of one that would fit (part number)?

Anyone have a pic or details about soldering a bridge on a stock Bosch rotor?


Wiring this thing could be interesting since I seem to have different color wires than the manual shows. You'll probably be hearing from me later on that...

Added the MSD setup to my 71S a couple of years ago.

1. Wiring the unit is pretty straight forward. The importance of "robust" power and ground connections to make this setup work right and last a long time cannot be overemphasized.

2. You can add the recommended ignition wires later. I used the stock wires to get everything running, then switched over to a set of Jacobs wires. Use these wires with plenty of silicone grease in the boots if you ever want to get them off the plugs!

3. I also used the stock rev-limiting rotor but soldered heavy gauge buswire across the resistor. Again, clean connections make sure you do not create a cold solder joint.

4. Getting the tach to work may was my biggest challenge. Make sure you have continuity from the engine compartment to the tach signal wire.

5. I was able to open up my plug gap to 0.040 in. with this setup.

Plenty of info and diagrams posted on this previously here. Go slow and document your changes in case you need to backtrack. Best of luck!

Andy

'71 S
'88 M3
'99 748

Thanks for the info Andy.
So far I think I've collected every diagram and description ever posted here. Seems like the tach thing depends on what year tach you have. Some people report it working with no tach adaptor, others report no tach even with the adaptor. Guess I'll have to wait and see with that.

I got a used MSD box, and it seems to have wires (like pink) that aren't on the diagrams in the manual. MSD tech hasn't been much help so far. Some show that they go to the "mag", but I have no idea what that is, or if these wires go unconnected.

Steve

MSD
 

Hello Steve

This is a diagram of my setup ...
http://forums.pelicanparts.com/uploa...1117297534.gif

do you have good weather Steve in your area ?
here in Quebec it is very bad since the begin of the month...

Ray

Hi Raynald,

Nice to hear from you. Thanks for the info and the illustration. The problem (well one of them) is there is no white wire in the main bundle coming out of the box. There is one on the other end, but I thought that would be the tach output. I always seem to end up with some drama.

Weather... We've had something like twenty days of rain so I feel your pain.

Steve

Steve,

Make sure you use a matched MSD coil, not a Bosch blue or any other as the resistance is not set correctly.

Magnacore KV85s work great for the plug wires eliminating the Breu connectors that are...well...junk.

Good luck,

no tach adapter needed for a '73.5 car - I posted before on this and you can search that thread up to see if anyone with your year posted results; otherwise, it's hit or miss

post your results

Definitely convert to Crane or Pertronix if you are worried about burning out the rotor. Medium investment up front, but you'll never burn out a rotor or have to adjust points again.

nice advise but I don't understand how the Crane or Pertronix would prevent speed limit rotors from toasting ?

They don't have rotors; they are optical/magnetic.

Thanks guys-

I did upgrade to the Crane optical, but it does still use the rotor. It seems to be an issue with some, but not all (burning up rotors).

Does anyone know if I can just get some Accel spiral wires and apply my ends? All this stuff is killing my budget, so I really don't want to spend a fortune on plug wires if possible. The MSD stuff all says "warning" do not use with solid core wires. I never know if that just means it may not work as well, or if means it will damage the MSD parts.

What is bad news about a Bosch blue coil and the MSD unit?

You can't use it. They are non-compatible. You need to replace with something like the MSD Blaster 2.

Here's why I ask. I just paid a mechanic to install both an MSD and a new coil. Long story, because this is the type of work I undoubtedly would rather do myself. But, since he did it, I didn't do any homework on the parts because I trust him. Anyway, it's got a 6AL and a Blue coil on it and it seems to run fine.

Interesting; I could have sworn I read recently that the blue coil was not supposed to work or at least fail quickly. I'd search "MSD blue coil" and see what can be found.

I will do that. I wonder what the reasoning is, though.

As for the technical reasons, I don't know. I only have Pelican hearsay on this one.

Dave:

Your MSD will start and run OK with Bosch blue coil; you simply lose 4-6 HP. :)

I've seen this several times on the dyno and its due to the wrong impedance of that Bosch coil with the MSD and ignition's performance is degraded. Further, one can suffer an MSD failure since its drawing too much current with the incorrect coil.

My suggestion would be to either use the MSD High-Vibration blaster coil or HVC one; you (and your engine) will be very happy,...:).

I was waiting for your responce Steve...You went straight to the heart...HP loss! :)

cheers,

Can anyone comment on the plug wire situation?

You CAN use the stock Beru wires. Just not the best -- although if your saving money...

Next service, get the KV 85 Magnacores (rennsport systems has em.) I think they are around $200.00 for the set...

Yessir,........:)

Do not use any solid core wires with MSD's. They MUST have suppression wires for EFI elimination and better coil saturation.

Magnecor, MSD, and Moroso spiral-wound suppression wires are all OK.

Thanks Steve. I think I'd better talk with the guy who worked on my engine!

search on solid core and (I think) Grady Clay...

msd seems out of the 911 loop - I guess we are a very small slice of the market for them

Randy:

There is a LOT more to this than meets the eye and yes, MSD IS well out of the 911 "loop",....:)

All one has to do is call them with a tech question/problem about a 911 and see what kind of an answer you get.

MSD's require a high level of EMI suppression to ensure that the ignition is reliable to 6K and beyond. Porsche uses solid core wires and puts their suppression into the notoriously unreliable Beru plug connectors. While its OK in some applications, using spiral-wound suppression wire works much better and prevents some misfiring issues that occur at high RPM.

Magnecor wires use their own plug connectors that have no resistors and they are FAR more durable in every way.

Porsche AG has been well behind current (pun intended) plug wire/connector technology here until their latest cars which use coil-on-plug stuff eliminating those infernal Beru connectors.

This is great info. Thanks guys. My little 912 needs every last hp there is out there to be had in order to be a competitive autocrosser. I'm really glad we're discussing this.

Thxs Steve. I never knew it would actually run on a blue coil or that it might endanger the msd box, just that you weren't supposed to use one...

LOL,......About 2 years ago, I had a major disagreement on that subject with my partner as he didn't think the coil made any difference. :)

After a few runs on the engine dyno using the same engine equipped with MSD 6AL's testing both kinds of coils, I made my point. :) :)

MSD's require a specific "load" on the amplifier to work properly much like speaker impedance on class A & AB amplifiers.

I have a Blaster 2 coil in my box of spares. I'm going to swap coils tomorrow and report back.

By the way, how about NGK wires? They aren't solid cores. Should work okay?

how are the ribs, ron? little jaunt still backed-up a cpl weeks?
ryan

24+8hrs and I just realized that broken bones will need months for repair.

Scuba&Free diving made me start thinking. Actually what started the thinking is the 20-30# Stripped Bass that are currently being slammed 200' from my 911. I'm so wasted I started about taking pics. Did a few nice ones on that current 2 Reg thread.

back to topic.. Is anyone doing a new MSD install? I have some ready made pics.

yes..good drugs will become your new favorite ally..;)

yep, back to our regularly scheduled topic.
ryan

Interesting. So is that a loss vs. running without CDI and Bosch coil or a loss vs. with CDI with Bosch coil?
The reason I'm asking is I installed a Crane CDI box on my '68 911, and I dynoed the car with the CDI connected and disconnected. I saw basically no gain from the CDI. I am wondering, does it take the correct wires and coil to realize the benefits of the CDI, or maybe there is some other reason I gained nothing from the CDI install.

Thanks

http://www.hostdub.com/albums/ValveF...comp.sized.jpg
Click for a larger image.

No tach adapter needed for a '74 Carrera.
My set-up:
MSD 6AL, MDS HV Blaster Coil 2, magnecore R-100 racing wires, denso Iridum IW-20 spark plug .39 gap, new distribuitor cap and petronix on my tool box waithin to be installed

my last week thread

Joe; I think that the performance gains of a lot of ignition systems are oversold. If a car has an ignition system that provides a strong enough spark at the right time, across the full rev range -- well it doesn't get any better then that. The Porsche 911 ignition system pretty well fulfills those requirements with the following exceptions.

1) The very early car's had a tendency to foul plugs. The original Bosch electronic ignition system pretty well fixed that.

2) Cars with 2.0 heads (like yours and mine) and high compression pistons have a combustion chamber (at TDC) which has too much distance (and too many obstructions) between the spark plug and the outer edge of the cylinder. As a result it's not uncommon to have the cylinder not ignite (or not combust completely) at low rev's with the throttle closed (which causes the combustion and mixing to slow down even more). Using an multi-spark ignition gives the ignition system a "mulligan" if the initial spark fails to ignite the mixture. It occurs later in the cycle, but a late ignition is still better then none. As a result in my car it idles better, and runs better under light throttle and engine speeds < 3000 RPM. Above 3000 RPM I doubt it provides any real improvement over the stock system.

Finally, replacing the points with something like a crank-fire system eliminates a wear item in the system. As a result it can't wear out of spec like points can if they are neglected or set incorrectly.

For the most part that's it. Looking at your dyno chart, I can see a very clear and significant improvement at 2300 RPM. Given that your profile says that you like to autocross, I would think that this would be meaningful.